Secure the bottom of the leg curl attachment as shown in the video. Put an airex pad with a towel over it, under your knees. The towel will provide some traction. The airex pad alone can get slippery. Hook your heels in and lower yourself while keeping a straight line from your shoulders to your knees. Add bands or use your hands to aid in pulling yourself back up. Build yourself up to the point where you can do these without any assistance.